1. Field of the Invention
The invention is directed to a shock wave generator for an apparatus for non-contacting disintegration of calculi in the body of a life form, comprising a housing filled with a liquid, a membrane closing said housing and connected thereto along the edge thereof, and comprising means for pulsed driving of the membrane.
2. Description of the Prior Art
German published patent application No. 33 12 014 discloses such a shock wave generator. In the known shock wave generator, the membrane is electromagnetically driven. The shock waves emitted by this membrane are focussed onto the calculus, for example, the renal calculus of a human, by means of suitable measures in order to disintegrate this calculus.
The membrane of the known shock wave generator is secured such to the housing that it is firmly clamped along its entire edge. This leads thereto that the membrane, when driven pulse-like, is exposed to sudden bending stresses which can lead to overstressing of the membrane and, finally, to the outage thereof. Also disadvantageously occurring as a consequence of the deformations of the membrane connected to the bending stresses is that the shock waves generated with the known shock wave generator deviate from the desired ideal with respect to the shape and the pressure distribution in the pressure front, this leading to the fact that the shock waves can be focussed onto the calculus to be disintegrated to only a limited degree, i.e. the obtainable focus exhibits a relatively large three-dimensional extent, this being deleterious to the efficiency of the shock waves.